Well today Im scratching my head cause im not able to boot into Vista heres the scenario...

I have a few computer set-ups in the basement and this one is actualy for sale so its not plugged all the time. Asus Rampage Extreme x48 with a single drive dual boot (Vista Ultimate 64bit default and XP PRO 32bit). I installed a new pair of memory turned it on, not realizing the monitor DVI was unplugged from the monitor, I reset the pc once cause I thought it does not like the ram. So I plugged the monitor and got to the bios and changed my ram settings, boots fine on XP, played COD5 for an hour so ram is stable...lol, but black screen on Vista. So fine I said ived corrupted some files, went to safe mode and just freezes loading drivers. I booted on to my Vista CD and would get blank screen after it says loading. So weird, how do I fix or re-install if I cant get the CD to go through Vista installation, even tried my windows7 CD and same thing.

Is it possible there's something wrong with the memory above what a 32bit OS can access?

You are totaly right...its 2x2GB OCZ Reaper I just bought and took one stick out and it boots fine on Vista Ultimate 64bit. Ill have to do some memtest on these then and see if any of my board slots have issue.